As it is well known by those skilled in the medical field, urinary incontinence is a serious urological problem, consisting in the incapacity of the individual to retain the urine, frequently causing the involuntary emission thereof.
Urinary incontinence may result from several factors (congenital diseases, acquired diseases, consequences from surgery, etc.). Among the most frequent causes, the following can be mentioned: prostatectomy (partial or total removal of the prostate); epispadias (congenital malformation in which the urethra opens before the end of the penis; injuries in the spinal medulla; fracture of the pelvis; neurogenic bladder, etc.
Undoubtfully, urinary incontinence causes significant impacts in the patient's quality of life, since the involuntary emission of urine is a discomfort, resulting in hygienic and social problems, provoking the reclusion of the patient, impairing his social and professional activities and very often his sexual performance.
Moreover, this disturbance usually brings emotional problems to the patient, who becomes depressed and stigmatized.
Many studies involving several age groups revealed the prevalence from about 17 to 41% of urinary incontinence in the whole population of the planet, consisting therefore in a public health problem. In the United States, for instance, more than 10 billion dollars are used yearly for the treatment of urinary incontinence, this value surpassing those values directed for the treatment of other diseases, such as revascularization of the myocardium or dialysis.
Thus, it can be stated that urinary incontinence is a medical, social and epidemiological problem with very important economic effects.
For all these reasons, urinary incontinence is one of the problems that have been widely studied by many researchers, who are often frustrated for not reaching solutions which are both technically and economically adequate for the problem. Such disease has also caused disappointment in many surgeons, when said symptom arises as a sequella of surgical procedures.
Many have been the methods used for treating urinary incontinence, among which the following can be mentioned: expectant therapy, pharmacological treatment, electronic devices, several surgical procedures and, finally, artificial sphincters. Such methods have been employed in different circumstances and their results have received praises in some instances, but severe criticisms in others.
Many types of prosthesis have already been provided to treat urinary incontinence, such as those from Foley (1947), Berry (1961), Kauffman (1973), Scott (1974) and Rosen (1976), besides Cunhinham's tweezers. All these models were constructed with the aim of causing urethral compression. According to this basic principle, the mechanical compression systems were developed, until the artificial sphincters with self-regulating pressure were provided, such as the various models manufactured by American Medical Systems.
The most modern system used nowadays is the AMS 800, also produced by the above cited company and commercialized since 1983. This model of sphincter comprises an inflatable sleeve, which is implanted in the patient around his urethral canal and connected with a pump, which comprises a valve, a rechargeable delay resistor and a pressure deactivating button. Said pump is also connected with a pressure regulating sump in the form of a balloon.
This artificial sphincter is kept constantly activated, i.e., the sleeve surrounding the urethra is kept permanently inflated, at a predetermined pressure controlled by the sump, thus pressing the urethral canal and avoiding the passage of urine. Only when the patient presses the pressure deactivating button is that said sleeve is deflated, thereby not pressing the urethral canal anymore and, from that time on, allowing the urine to pass. The emission of urine is thus controlled by the patient with urinary incontinence.
One of the inconveniences of this current model of artificial sphincter is the large number of complex connections, which are difficult to handle and increase the risk of mechanical dysfunctions. Another inconvenience resides in its implantation method, which requires a very laborious and complicated surgery, with many details to be strictly followed in order to avoid harmful intercourses, such as infections and erosions.
Another problem of this type of sphincter relates to the installation thereof, which requires skills, for example, to mount the system, to determine the adequate pressure to obtain the continence, to know exactly which details should be avoided so as not to result in the complications cited above and how to treat said complications when they arise.
Finally, a very relevant aspect which limits the application of said artificial sphincter in everyday practice is its cost. Unfortunately, this device is not accessible to all persons, since its value cannot be paid by many patients. On the other hand, this high cost also imposes limitations to the physician, who sees this type of therapeutics as the only possible way of treatment.